The present invention relates to a device for the treatment of water to reduce the buildup of scale and in particular to a device wherein the water is subjected to a magnetic field as it pases through an annular, elongated treatment chamber.
A problem which is quite prevalent in systems and apparatus which use large amounts of water, such as boilers, dishwashers, ice machines, and the like, is that of scale buildup on the surfaces which come into contact with the water. This is especially troublesome in areas where the water has a high mineral content so that it is necessary for the water to be "conditioned" either by chemical action or by magnetic water treatment devices of the general type to which the resent invention relates.
One such magnetic treatment device is disclosed inU.S. Pat. No. 3,951,807 to Charles H. Sanderson and comprises an elongated magnet having a multiplicity of longitudinally spaced poles encased in a non-magnetic jacket and concentrically positioned within a galvanized outer casing made of a magnetic material. The jacketed magnet is centered by means of a pair of stepped collars secured thereto which in turn are centered by means of a pair of flared inserts.
U.S. Pat. No. 2,690,842 teaches a fuel line cleaner device having an elongated magnet enclosed within a tubular casing threaded on both ends to receive a pair of fittings, which in turn are provided with supporting webs formed of non-magnetic material having threaded hub portions centrally supported by a pair of spaced members. The magnet is threaded at each end and engages the respective hub portions of the supporting webs so that it is centrally supported within the enclosure.
Another magnetic water treatment device, one which is presently commercially available, comprises an outer casing of magnetic material, an intermediate casing made of plastic and an elongated permanent magnet encased within a plastic jacket having helical vanes which support the magnet centrally within the intermediate casing. Non-magnetic end caps are threadedly secured to opposite ends of the intermediate casing and O-rings are compressed between flanges on the end caps and the outer casing.
Magnetic treatment devices generally of this type are well known and prevent the buildup of scale by causing the calcium and other minerals present in hard water to form, instead, a loose slurry which can be easily removed from the system by blowdown or flusing. In many applications such as furnace humidifiers, for example, it is necessary that the device be contained within a fairly small housing and for this reason, available space is at a premium. The effectiveness with which the water is treated depends on the intensity of the magnetic field within the treating chamber and the effective length of the chamber itself. Accordingly, it is desirable that the chamber be free of any obstructions which may occupy otherwise available treatment space, and for the water to be directed into and completely occupy the annular treatment chamber as quickly and in as short a distance as possible after it enters the device.
A further consideration is that the strength of the magnetic field produced by the magnetic be confined solely to the annular treatment chamber so that all of the available flux will be utilized. An important factor in assuring this situation is to completely magnetically isolate the magnet from the supporting structure and to complete the magnetic circuit by means of a ferrous casing which surrounds the magnet and which is also magnetically insulated from its supporting structure and from the magnet.